The present invention relates to a single-chip microcomputer.
A single-chip microcomputer including a CPU (central processing unit), a ROM (read only memory) and a RAM (random access memory) has been conventionally known.
In the case where the single-chip microcomputer is used as the so-called microcontroller, a CPU clock signal having a frequency in accordance with an object to be controlled is selected. However, access times of the ROM and RAM cannot be changed. Therefore, there can arise mismatching between the cycle time of the CPU clock signal and the access times of the ROM and the RAM.